/Engine/Source/Runtime/Engine/Classes/Kismet/BlueprintPlatformLibrary.h
The list of possible device/screen orientation for mobile devices
namespace EScreenOrientation { enum Type { Unknown, Portrait, PortraitUpsideDown, LandscapeLeft, LandscapeRight, FaceUp, FaceDown, PortraitSensor, LandscapeSensor, FullSensor, } }